Are you trying to have the arduninos do something (operate lights, work some robotics) and control them by sending MIDI messages?
That's certainly do-able. The problem is in what you mean by "a variety of". If you have several different types of things that you want to control with MIDI, it depends on how complex each of those types of things is. In effect, you have two problems - writing some code that will catch and interpret MIDI messages, and writing the code that makes your various devices do whatever it is that they need to do.
How were you thinking of settng the MIDI channel on each arduino? DIP switches? Hard-coded into the sketch? Are you looking at building a dozen or so identical pyrotechnics units, or do you need to control 5 different robotic arms, each of which needs its own code?
What you are describing is potentially a big job.
If you are looking for directions on how to do it, I would:
Write code that operates your equipment using messages from a serial input, and get it right using the IDE.
Write code that uses an existing MIDI library to interpret MIDI messages (however you do that).
Hook 'em together.
But people will need some more info before you can get replies here any more useful than that.